South Sudan faces one of the world's most acute intersections of climate vulnerability and gender inequality, yet women remain systematically excluded from climate finance decision-making and community-based adaptation (CBA) programming. This study examines the structural, institutional, and socio-cultural barriers that constrain women's participation in climate adaptation finance in South Sudan, while identifying evidence-based opportunities to advance women-led resilience. Drawing on a systematic synthesis of 43 empirical studies published between 2010 and 2023, combined with a mixed-methods analytical framework grounded in feminist political ecology and intersectional vulnerability theory, the paper develops a Gender-Climate Finance Nexus Index (GCFNI) and a Women's Resilience Quotient (WRQ) to quantify gaps. Findings reveal that women-headed households access fewer than 15% of available climate finance instruments compared to 38% for male-headed counterparts. Five critical barrier domains are identified: mobility restrictions, land tenure insecurity, digital exclusion, financial exclusion, and patriarchal institutional norms. The paper argues for gender-transformative financing architectures, community-led accountability mechanisms, and multi-scalar policy reforms aligned with the UNFCCC Gender Action Plan and the African Union's Agenda 2063. Recommendations span three levels of intervention: household, community, and national policy.